Engine cooling apparatus



March 2, 1954 Filed Feb. 24, 1950 3 Sheets-Sheet 1 WATER HEAT EXCH.

L HEAT EXO ENGINE LUBRIOATING OIL FIG.2.

THOMAS J. BAY

ATTORNEY 35 INVENTOR March 2, 1954 T. J. BAY 2,670,933

ENGINE COOLING APPARATUS Filed Feb. 24, 1950 3 Sheets-Sheet 2 FIG.3.

INVENT OR THOMAS J. BAY

ATTORNEY March 2, 1954 T. J. BAY 2,670,933

ENGINE COOLING APPARATUS Fi-led Feb. 24, 1950 3 Sheets-Sheet 3 FIGA.

INVENTOR THOMAS J. BAY

ATTORNEY Patented Mar. 2, 1954 UNITED STATES PATENT OFFICE 2,670,933ENGINE COOLING APPARATUS Thomas J. Bay, Iiyden, Wash. ApplicationFebruary 24, 1950, Serial No. 146,122 7 2 Claims. (oi. 257-2) (Grantedunder Title 3656K S. Code (1952),

see. l

The invention described herein may be made and used by or for theGovernment of the United States for governmental purposes without thepayment to me of any royaltie thereon or therefor.

This application is a continuation in part of my copending application,Serial No. 775,512, filed September 22, 1947, .now Patent 2,498,637,issued February 28, 1950.

This invention relates to cooling systems for internal combustionengines and to apparatus for use in such systems, and particularly tosystems of'the type disclosed in my Patent No. 2,365,166, grantedDecember 19, 1944. The principal objects of the present invention are toprovide apparatus for use in systems like those disclosed in thatpatent'and in this specification, and also to provide a system improvedin certain respects over the earlier one.

. The system disclosed in Patent'Nd. 2,365,166 L constitutedimprovements in internal combustion engine cooling wherein the enginecooling water after having passed in heat exchange relation with a primecoolin medium is then passed in heat exchange relation with thelubricating oil One desirable possibility in such a system is to providefor the rapid elevation of temperature of both the water and thelubricating oil on starting the cold engine. This serves to minimizeengine wear, render the installation more reliable in serviceand reduceexpense of maintenance.

'1' While the system provided in the above mentioned prior patent hasgiven good service and in many applications is very satisfactory, I havein the present instance devised animprovement on that systemparticularly valuable to prov-ide'for bringing the lubricating oil toproper operating temperature as rapidly as possible after starting acold engine to provide for close control of lubricating oil temperaturein cases where the engine design provides for relatively large rise inlubricating oil temperature during its circulation through the engineand to provide automatic maintenance of the cooling system in case ofvalve breakdown. I have further devised improved apparatus for use inthe new system as wellas in the system previously disclosed.

With the object of clearly disclosing the invention, the accompanyingdrawings will be discussed in connection with the description aspresenting preferred embodiments from which numerous departures may bemade within the scope of the invention.

' Figure 1 is a representation of a complete system for controlling thetemperatures of water and of lubricating oil for an internal combustionengine.

Figure 2 shows a heat exchanger with a preferred form of thermostaticvalve incorporated in its structure.

Figure 3 shows a heat exchanger with a modifled form of valve.

Figure 4 shows a further form of heat exchanger involving sectionalstructure and a plurality of valves. I I In Figure l the major elementsof the engine cooling system comprise the internal combustion engine I,water heat exchanger .2 and oil heat exchanger 3. The engine heatexchange medium leaves the water jacket by pipe 4 and returnsthrough'pipe 5. The entire how or any portion of the circulatinlubricating oil is taken from any suitable point in the lubricatingsystem at 6 and returned at 1.

Both heat exchangers are represented as being of the type in which twofluids are passed in heat exchange relation with each other but withoutmixture of the two fluids. In order to convey this idea the two fluidsare shown as passing through separate coils within the exchangers. Thusin exchanger 2 the primary cooling medium passes through coil 8, and theengine'jacketwater through coil 9, and in the oil heat exchanger 3 waterpasses through coil Ill while the lubricating oil flows in coil I l. I

The various elements of the piping represented for conveying the severalfluids involve a section I3 to the water heat exchanger, a section 14between the two-heat exchangers, a portion Hi from valve l!- -to valvel9, and a section l6 constituting a by-pass around the oil heatexchanger to pipe 5. Valves-ll and l9are thermostatically controlledvalves hereinafter fully described. In the case of valve ll the controlelement [8 is in thermal relationship with the water leaving the engine,while the thermostatic element 29 of valve [9,

though the valv controls water circulation, is in thermal relation with,and controlled by the temperature of the oil leaving heat exchanger 3.

Figure 1 is diagrammatic in nature and does not, save in a generalmanner, indicate the construction of the various elements.

- While it appears that external pipes and valves are employed, this isnot necessarily true, as will appear later from description of my newlydevised heat exchanger. The description will proceed by setting forththe system as applied to a marine engine installation wherein sea waterconstitutes the prime heat exchanger medium flowing in coil 8, but it isto be noted that the heat exchanger 2 might be of any type capable ofcooling the fluid passing in coil 9. Since the present systemissmodified particularlyttorimprovedpere formanceirirnconnectiomwithrapidly hringing:the engine to an efficient operating temperature, thisoperation will be first described and is as follows; a

On starting of the engine, cold water under the influence of the enginewater pumpzfiowslinthe; direction of the arrows at pipes 4 andj.Thewater is forced to flow through pipe IFsihce the valve I! is closedto flow there, throughtby -oper ation of its thermostatic element It.For purposes of this diagrammatic presentation, val'vel'F is indicatedas of a type allowing flow-.in 011.8?01 both of two directions, flowbeing allowed through. l3 and i5 when the water at is has reached apredetermined. elevated temperature and through l5 only at lowertemperatures. Valve lilisof, the type whichl have in.inypreviouspatentspecification described as. av three-way valve... Its.operationisto dir ct fluidfiow in..cne-or theother of two directions inthis case to pipes 2! or Iii-clependinguponthe temperature of. theoi-laffecting the. element 2B; When. the. thermostat- 20 is. at a lowtemperature, action of valve is i'sto. send all the. water. throughpipeli. and thusthrough coil Ill ofheat exchanger 3. Thereforeunderstarting. conditionsthe course. of the engine. jacket water. will. be.in. sequence. through. pipes. 4, l5, valve I9, pipe 2!, coilIlland'pipe. hackle-the engine jacket. completely by-passed', asis'.evident,.andf thus the enginewater, subjectlonly to a minimumamountof heat radiation, will. have its temperature. raised rapidly bytheheatsuppliedlby the engine. Fur.- ther all the. engine. waterflowsthroughheat exchanger 3'; Since in practically allinternal'combustion engines a greatdeal more. heat passes. into the cooling waterthan passes into. the. lubricate ing. oil, it will be seen that the.heat exchange relationship between. the rapidly heating water and theoil in exchanger? will serve to increase the temperature of. the coldoil rapidly, whiclLis one ofthe mainobject's of the system. When .theoil? is. at-properoperating. temperature, valve. t9

will act to. control the amount. of, water. passing.

through. I 0. fitomthe engine. When-fulloperating conditions. have beenreached all. thecooledwater from heat. exchanger 2. will. pass through.heat exchanger 3, while part of the water willlby-pass both. heat.exchangers and return tdthe; engine. Incase thecil is ,cooled to too.low: atemperature, valve. 1 a will open. partialhc. allowingtsomez of;the hotwater. from. valve. iii to pass. through-pipe 2]. to. the oil.heat exchanger. 3. In. this manner: a very close control. ofthealubricating-oil tempera. tureispossible. Ehisis of especial benefit:in-rCDn"? nection with. engines .usinga: small quantity oi oil which.may have to absorb a great. deal of heat athigh power. operation of theengine.

Figure 2 indicates. a heat exchanger containing the essential. elementsfor constituting. the. water heat exchanger 2 showninthe. diagramofFigure 1. This-heat. exchanger. comprises a cylindrical shell 2-5, waterchestsifi-and 21 at either end. of theshell anda tube. assemblycomprising. headersor tube sheets 30.. and 31. andtubesSZ. Inletill.and: outlet. 29. are, provided for the. fluid which will flow.exteriorly or". thatubes. 3.2, in. the. case here. described. said fluidbeingsea water. In.-

addition to the heat exchanger tubes, thereis pro.=

The. water heat.- exchanger 21 is vided a by-pass tube 33 also securedin the tube sheets 39 and 3!. Water inlet 34 is provided in the Waterchest 26 and an outlet 35 in water chest As in integral portion of theinlet 34, there is an extension constituting a valve body 31 havingopenings at in its sides. A valve closure 38, operated by a'thermostatic element: 3.9, serves to controlsfiow through-theopeningsgML-and, indirectly, through the by-pass tube 33. As will beapparent from the drawing, valve closure 38,

when in its extended position, will uncover openi'ngsdll. When in itsretracted position the closure 38 willeut off communication from theinlet 3'4 to the water chest 26. At intermediate positiensthe water-flowwill be divided. Communication from inlet 34 through tube 33 is allowedat alltimesz' Thermostat element 39 is assumed to expand when theincoming water is hot and contract when it is cold, it beingcontemplated that suitable adjustments may be provided in knownmanner... The element-may be of. any. oitha-bel- 10WS, bimetallicpr.other type;

As applied in the. systemaccording. toFigurel, thespace within-theshell.2.5. correspondsto. coil 8. The assembly of tubes 32 corresponds to coil9,. the. thermostat valve to valve. [1,. tube 3.32110 by-pass-pipe l5,and element; 39 to element l8f.

In operationsea water. will.circulatethrough. the shell around thetubes. Uponst'artingthe engine, cold water from the. engihewillienter.inlet 34;. from pipe l of Figure 1, and pass directly. through valvehousing 37'; valve. 38, andby-pass tube 335,.the downstreamend" of.which 15-6.0111.- nected to tube 35 of Figure. I. Since. the water. iscol'd,.thermostat 39" is contractedandiportsl 411 in: valve housing}?are closedby valve. 38 so all. the water comingfrom the engine mustpassinto; tube it of Figure l" which. conveys it to threeway thermostaticvalve I'9of Figure 1'. Sincethe lubricating oil circulating through tubeT from the. oil heat. exchanger 3 is also cold. when the engineisstarted; the thermostat bulb. Zllin thermal contact with the cold oilin pipe T causes three-way valve l9 todivert the entire quantity ofwaterentering it from tube. 15 to tube 2|, allowingnone of it to passjntotube Iii. Thustlie flow of jacket water when the cold engine is: firststarted'is as followszthrough pipe 4' to. valveSB; to by-pass tube33,.to tube. l5,',throug h-valve 1.9. to pipe 2.! through the. jacket.water CiICllil'j'jOf the. oil heat exchanger 3,.andback, to the engine.through tube 5.

Since the. cooling tubes. of. the water. heat; ex changer are. being.by-pas'sed, the heat. absorbed by the jacket water. in the. engineisnotbeing C1155 sipated and the jacket. water rapidly increases towardthe. desired operating. range. When. it reaches: the. desired.temperature the. thermostat 39.. expands. gradually opening ports. 4W;intvalve housing, 3.7. and permitting sufficient. jacket. watch flowthroughthe cooling. tubes: 32v for. cooling; as: necessary to: maintaina constant temperature of. the: jacket water passing from. theenginethrough. tube 4;. This cooled. water is. discharged from tubes. 32. intowater chest 27,. and thence: outoi the water heat exchanger: throughoutlet; 35 and: into tube M. of Figure 1.

It will be noted. that" jacket water. isnot. ad-- mitted. to coolingtubes. 32.: until. its. temperature, leaving the engineshas beenelevatedtonperatin range. Prior tog-this.timaalltheheat absorbed. by.the;- jacket. water: flowing through. the engin is. available forheating; the. lubricating.- oil; in. oiLheat-exchanger. 3-. In this waythe.-;.lubricat ingoil is. rapidly heated to.- the: desired. operatinrange. When the lubricatingoll approaches the desired temperature;thermostat bulb actuates three-way valve i9 and causes a division offlow'of jacket water at this point, i. e., part of the hot jacket wateris permitted to'circulate directly back to the engine through pipe 5 andthe remainder continues to flow through pipes 2| and M to the oil heatexchanger. Since the lubricating oil is heated more slowly than thejacket water when the engine is started, by the time'hot jacket water ispermitted by valve l9 to flow through pipe 2|, cooled jacket water fromthe jacket water heat exchanger is flowing through pipe [4 into whichtube 2| discharges, and under this intermediate condition a mixture ofhot and cooled jacket water flows into the oil heat exchanger.

We may now consider the conditions obtaining when the engine has beenoperating for some time and temperature conditions have stabilized.Valve I! is now dividing the flow of jacket water so as to maintain aconstant temperature of the jacket water leaving the engine. Valve I9 isdividing the flow of hot jacket Water, entering it from tube [5, betweentubes 2| and i6. Just sufficient fiow of hot water is permitted throughtube 2| to dilute the cooled water coming from the water heat exchangeras necessary to keep the lubricating oil, flowing to the engine from theoil heat exchanger through pipe I, at the desired operating temperature.The balance of the hot jacket water flowing into valve [9 from tube l5passes through tube It and combines with the jacket water issuing fromthe oil heat Thus, by proper initial exchanger in pipe 5. adjustment ofthermostatic valves l1 and IS. the temperature of the jacket waterleaving the engine and the temperature of the lubricating oil enteringthe engine are both automatically maintained within the desiredoperating range, and at the same time the temperature of the jacketwater entering the engine can be reheated to a temperature approachingor even higher than the temperature of the lubricating oil entering theengine.

Figure 3 illustrates a heat exchanger and valve of a modified design.All parts are similar to those in Figure 2 and identical referencecharacters are used, except for the valve closure which is referred toas 48 since it is diiferent from the valve closure 38. The action ofthis valve is somewhat different from that of Figure 2 in that positivecut-01f occurs in both positions. This form of valve is capable ofclosing communication with by-pass tube 33. In operation of this device,cold water entering inlet 34 will pass through openings 29 and by-pass33. When the water has warmed sufliciently action of the element 39 willuncover openings allowing an increasing portion of the water to passthrough tubes 32, water chest 2?, and outlet 35. When the valve isentirely extended, no water is by-passed by reason of the seating of thespherical face on seat 56. A further difference is that by-pass 33discharges into water chest 21, rather than having a separate outlet.

Figure 4 represents a modified type of heat exchanger for use eitherwith an oil or water system, and comprising a plurality of thermostatcontrolled valves. Reference characters are applied to the same elementsinvolved in the construction of Figure 3. Major differences involvedcomprise dividing the tube assemblies by providing a plurality ofIcy-pass tubes 33 with their associated thermostat valves. Action of thevalves will be identical with that heretofore .described. Provision ofthe plurality of valves.en-.- tails a number of advantages, prominentamong which are use of standard sizes of valves for various sizes ofheat exchanger, and possibility of satisfactory operation, even thoughone or more of the valves should fail. It is contemplated that thevalves will be so constructed that upon failure they will act to opencommunication with the tubes 32 in order to utilize the full heat ex-'change capacity of the system. This may be accomplished by constructingthermostat valves 39 so as to contain fluid at sub-atmospheric pressure.In case of a leak in the bellows wall of the thermostat air enters andexpands the chamber thereby closing the short circuiting bypass 33 andinsuring maintenance of the fullcool ing action of tubes 32. v

The valves may be of the type shown in Figure 2. I

In the heat exchangers described above, the by-pass is as shown in orderto secure the advantages of integral construction of the valve.Negligible heat exchange will occur due to the relatively small surfacesexposed.

It is believed that advantages not specifically referred to will beobvious, as will modifications not departing from the scope of theappended claims.

I claim:

1. Heat-exchange apparatus comprising a casing having inlet and outletopenings, header plates disposed in said casing for forming inlet andoutlet chambers, heat-exchange tubes carried by said headers incommunication with both chambers, a by-pass tube having one end incommunication with said inlet chamber and the other end projectingoutwardly through said casing, and valve mechanism for distributinginfluent between said exchange and said by-pass tubes, said mechanismincluding a tubular valve housing projecting from said inlet opening tosaid by-pass tube, an open-ended sleeve valve slidably mounted in saidhousing, and heat-responsive means actuated by the temperature of saidinfiuent for slidably moving said sleeve valve, said valve housing beingprovided with a port permitting fiow outwardly from the housing intosaid inlet chamber, and said heat-responsive means operating to movesaid sleeve valve to close said port upon low temperature influentconditions and to gradually open the port in response to increasingtemperature gradients, whereby distribution of said influent betweensaid by-pass and said heat-exchange tubes is automatically andinfinitely variable, the openend sleeve valve at all times permitting a,portion of said influent to by-pass said heat-exchange tubes fordelivery in a relatively unmodified temperature condition at a desiredlocation.

2. Heat-exchange apparatus comprising 3, casing, header plates disposedin said casing for forming inlet and outlet chambers with the easing endwalls, heat-exchange tubes carried between said headers in communicationwith both chambers, a by-pass tube having one end in communication withsaid inlet chamber and the other end projecting outwardly through saidcasing, and valve mechanism for distributing influent between saidexchanger and said by-pass tubes, said mechanism including a tubularvalve housing disposed about the inlet chamber opening of said by-passtub and projecting from said disposition outwardly through said inletchamber casing walls, an infiuent conduit com Z witmsaidi tubularhmising. QUIE ifiB-Qf nasmg: wail; PBIIL' X-ZdLSIBBVG': valve: shay abmmounted; in: saizh musing within: said: inlet ehamben; saidhausingzbeingformerchwith a ort permittin flaw outwardly fmm it;inm=sa-idiin- 1.81; chamhfin; amtl hBEt'rIZESQDBSiVB: means; dis-=Qasad: in:. said: housingzbetweenz said: influent con d'iuit; ami said;pant; for; actuating said. valve; said mat-responsive means; being;adapted: to; mom: saiddvalveto closmsaid nomugonlow tempera 31mminfiuent conditions; and to:- gmduallyopen said: port. in: responsg toincreasing temperature gyadien=i1s-,-. whereby; the distribution; ofsaid; influent. between said byi-pass. and; heat-exchange times1 isautomaticallyand infinitelyvaniablaiha ogenrend sleeve- V&1Vfi--,a-tall!times permitting a. pant-ion: of. said, infiuent :tnz by-p assrsaidiheatrexchanges tubes for delivery in:anizelaiiiviely unmodir fledtemperature canditionhat-i a; desirecL location.

THOMAS J BAY,

& v R (mad: im thee filesoit this: patesii:

UNITED S'zT-ATESPATENTS" Number Gountry- Data,

232309" GIeakBriba'itr 1925 310:157 Great Britain Apr.- 25; 1 925

